Oxidation adversely effects nearly all edible fats and oils (i.e., lipids), as well as food products containing such fats and oil. Oxidation of such fats and oils in food products generally results in significant and undesirable changes in flavor, aroma, color, or other organoleptic properties.
Some fats and oils are especially susceptible to oxidation. For example, food products containing significant levels of polyunsaturated fatty acid functional oils such as omega-3-containing fish oils often have reduced shelf lives due to the oxidation of the oils. In addition to the undesirable changes in flavor, aroma, color, and other organoleptic properties, oxidation often reduces the beneficial effects associated with such functional oils in the human diet.
A large number of efforts have been made to increase the oxidative stability of fats and oils used in food products. For example, U.S. Pat. No. 4,525,306 (Jun. 25, 1985) provided various antioxidant compositions which were derived from herb spices to increase the oxidative stability of fats and oils; stability could be further increased by providing soft capsules for fats or oils containing the antioxidant compositions. U.S. Pat. No. 4,895,725 (Jan. 23, 1990) provided microencapsulated fish oil wherein unpleasant taste and smell as well as oxidation were inhibited. U.S. Pat. No. 5,120,556 (Jun. 9, 1992) provided a method for inhibiting lipid oxidation wherein a defatted corn germ composition was added to an unsaturated fat or oil or a food product containing such unsaturated fat or oil.
U.S. Pat. No. 5,166,375 (Nov. 24, 1992) provided an antioxidant composition comprising musizin and tocopherol for use in fats and oils. U.S. Pat. No. 5,514,407 (May 7, 1996) and U.S. Pat. No. 5,624,703 (Apr. 29, 1997) provided a blend of a cholesterol-reduced animal fat and a vegetable or cholesterol-stripped fish oil having specific ratios of linoleic acid and myristic acid; such compositions are reportedly oxidatively stable. U.S. Pat. No. 5,552,167 (Sep. 3, 1996) reported that high linolenic edible oils (e.g., soybean oil, canola) can be oxidatively stabilized by the addition of effective amounts of rice bran oil. U.S. Pat. No. 5,871,757 (Feb. 16, 1999) stabilized polyunsaturated oils against oxidation by the addition of an essential oil such as thyme oil, pepper oil, or clove oil.
U.S. Pat. No. 5,874,117 (Feb. 23, 1999) provided an oxidation-resistant food shortening including a blended vegetable fat composition having between 50 and 95 percent palm fat and between 5 and 50 percent corn oil. U.S. Pat. No. 6,033,706 (Mar. 7, 2000) provided a refining method wherein crude edible speciality oils could be prepared while minimizing the destruction of natural antioxidants and antioxidant precursors naturally contained in the starting oils. U.S. Pat. No. 6,162,480 (Dec. 19, 2000) incorporated polyphenols in oils to provide oxidative stability; the polyphenols were incorporated by soaking olive fruits in the oil for at least one day. U.S. Pat. No. 6,165,539 (Dec. 16, 2000) reduced oxidation of food supplements containing oils by preparing and/or storing the food supplements under controlled lighting conditions and/or low-oxygen conditions.
U.S. Pat. No. 6,287,579 (Sep. 11, 2001) used an antioxidant composition containing at least one tocopherol and an acid selected from the group consisting of kojic acid, malic acid, and ascorbic acid in esters of long-chain organic molecules derived from natural oils (e.g., plant, bean, seed, and nut oils). U.S. Pat. No. 6,448,292 (Sep. 10, 2002) provided an oxidatively stable oil composition containing a diglyceride and a triglyceride, wherein the diglyceride has at least 55 percent of the acyl groups being unsaturated acyl groups and 15 to 100 percent of the acyl groups being omega-3 type unsaturated acyl groups having at least 20 carbon atoms and wherein the triglyceride has at least 70 percent of the acyl groups being unsaturated acyl groups and 5 to 80 percent of the acyl groups are linoleyl groups.
Lactobionic acid (4-O-β-D-galactopyranosyl-D-gluconic acid; CAS Reg. No. 96-82-2) is a water soluble, white crystalline compound. It can be synthesized from lactose by oxidation of the free aldehyde group in lactose as carried out catalytically, chemically, electrolytically, or enzymatically. Harju, Bulletin of the IDF 289, ch. 6., pp. 27-30, 1993; Satory et al., Biotechnology Letters 19 (12) 1205-08, 1997. The use of lactobionic acid or its salts as additives in food products previously has been suggested for several specific applications. Calcium or iron chelate forms of lactobionic acid have been described for dietary mineral supplementation. Riviera et al., Amer. J. Clin. Nutr.; 36 (6) 1162-69, 1982. U.S. Pat. No. 5,851,578 describes a clear beverage having a non-gel forming fiber, and water soluble salts of calcium, with or without water soluble vitamins, with or without additional mineral salt supplements and buffered with food acids. The food acid buffering agent includes citric, lactic, maleic, adipic, succinic, acetic, acetic gluconic, lactobionic, ascorbic, pyruvic, and phosphoric acids, as well as combinations thereof. Calcium lactobionate, a salt form of lactobionic acid, has been approved for use as a firming agent in dry pudding mixes. 21 C.F.R. §172.720 (1999). Also, the possible use of lactobionic acid as a general food acidulent has been proposed, albeit without exploration or illustration. Timmermans, Whey: Proceedings of the 2nd Int'l Whey Conf., Int'l Dairy Federation, Chicago, October 1997, pp. 233, 249. This article generally describes lactobionic acid as being useful as an antibiotics carrier, an organ transplant preservative, mineral supplementation, growth promotion of bifidobacteria, or as a co-builder in detergents in its K-lactobionate salt form.
Siderohores are, in general terms, iron chelating agents which are expressed by microorganisms such as yeasts and molds (especially in low iron environments). Microorganisms use such siderophores to obtain iron necessary for growth. Typically, siderophores have been used for deferration therapy (i.e., treating patients with excessive iron loads) and/or as an anti-microbial treatment. See, e.g., U.S. Pat. No. 5,192,807 (Mar. 9, 1993); U.S. Pat. No. 5,371,234 (Dec. 6, 1994); U.S. Pat. No. 5,393,777 (Feb. 28, 1995); U.S. Pat. No. 6,013,647 (Jan. 11, 2000). U.S. Pat. No. 5,573,801 (Nov. 12, 1996) used antimicrobial compositions containing a lanthionine bacteriocin (e.g., nisin) in combination with a chelating agent (including certain siderophores such as desferri-ferrichrysin) as a surface coating for food products. Siderophores have also been reported for use in treatment of iron deficiency anaemia in both humans and animals (U.S. Pat. RE. 34,313 (Jul. 13, 1993)) and of iron chlorosis in plants (U.S. Pat. No. 4,872,899 (Oct. 10, 1989)).
There remains a need, however, for different methods to increase the oxidative stability of fats and oils which are to be included in food products. There also remains a need for antioxidant compositions which can be used in food compositions to increase oxidative stability. There also remains a need for methods to increase the oxidative stability of fats and oils which are to be included in food products using antioxidant compositions containing only natural or non-synthetic ingredients. There also remains a need for antioxidant compositions containing natural or non-synthetic ingredients which can be used in food compositions to increase oxidative stability. The present invention provides such methods and compositions.